Air conditioning apparatus for an automobile

Abstract

An air conditioning apparatus for an automobile in which a desired tension of a film damper is always maintained regardless of a movement of the film damper. A third shaft 14 is connected to a truncated conical-shaped first tapered pulley 21, and a fourth shaft 15 is connected to a truncated conical shaped second tapered pulley 22. The second film damper 18 is wound on the third and fourth shafts 14 and 15, and a second wire 20 is spirally wound onto the first and second tapered pulleys 21 and 22. The first and second tapered pulleys 21 and 22 are arranged such that they are oppositely tapered in such a manner that the amount of movement of the damper film 14 and the wire 20 is substantially equal, not only between the third shaft 14 as a drive shaft and the first pulley connected to the shaft 14, but also between the fourth shaft 15 as a driven shaft and the second pulley 22 connected to the shaft 15. Therefore, an excessive stretching and slackening of the damper film and the wire is prevented.

We claim: 
     
       1. An air conditioning apparatus for an automobile, comprising: an air duct having one end open to a cabin of the automobile, for generating a flow of air to be introduced into the cabin;   said air duct defining a pair of opposing walls between which a flow of air passes;   a blower arranged in the air duct, for generating a flow of air in the air duct;   means arranged of the blower for controlling a temperature in the air duct;   means arranged downstream of the blower for controlling a temperature of the air flow, and;   damper means arranged in the air duct for controlling a condition of the air flow in the air duct, said damper means comprising:   a pair of spaced-apart shafts each having an axis, and being rotatably with respect to said opposing walls of the air duct;   a film member having a first end connected to one of said shafts and a second end connected to another of said shafts, said film member having at least one opening through which the air in the air duct is passed, for controlling a condition of the flow of the air in the air duct and having first portion would on the one of said shafts and second portions wound on the other of said shafts;   drive means for imparting a rotational movement to said one shaft in such a manner that the film member is moved between said spaced-apart shafts by winding or unwinding the film member onto or from said one shaft to which the drive means are connected, and;   power transmitting means for transmitting the rotation from said one shaft connected to the drive means to the other shaft so that when a radius of said first portion of said film member is smaller than a radius of said second portion, said one shaft rotates at a predetermined rotational speed, and when said radius of said first portion is larger than said radius of said second portion, a rotational speed of said one shaft is substantially less than said predetermined rotational speed, thereby preventing said film member from being over tensioned during transmission of the rotation from said shaft to the other said shaft by said power transmitting means.   
     
     
       2. An air conditioning apparatus according to claim 1, wherein said power transmitting means comprise: a first rotating body connected to said one shaft and rotatable in the same direction as said one shaft, the first rotating body having an axis and defining an outer surface having radius which varies proportionally along the axis thereof;   a second rotating body connected to the other shaft and rotatable in the same direction as said other shaft, the second rotating body having an axis and defining an outer surface having a radius which varies proportionally along the axis thereof, and;   means connected to both of the first and second rotating bodies and in contact with the respective outer surfaces thereof, for transmitting a rotation of the first rotating body to the second rotating body.   
     
     
       3. An air conditioning apparatus according to claim 2, wherein said transmitting means comprise a wire member having a first end connected to the first rotating body such that the wire member is able to be helically wound on said outer surface of the first rotating body, and a second end connected to the second rotating body such that the wire member is able to be helically wound on said outer surface of the second rotating body, and; wherein a ratio of a distance between the axis of the first rotating body and a point whereat said wire member is detached from the first rotating body, to a distance between the axis of the second rotating body and a point whereat said wire member is detached from the second rotating body is equal to a ratio of a radius of the first portion of film member to a radius of the second portion of the film member.   
     
     
       4. An air conditioning apparatus according to claim 3, wherein each of said first and second rotating bodies have a helical groove formed on the respective outer surfaces thereof for receiving the wire member when wound onto the corresponding rotating body. 
     
     
       5. An air conditioning apparatus for an automobile, comprising: an air duct having one end open to a cabin of the automobile, for generating a flow of air to be introduced into the cabin;   said air duct defining a pair of opposing walls between which a flow of air passes;   a blower arranged in the duct, for generating a flow of air in the air duct;   means arranged downstream of the blower, for controlling a temperature of the air flow, and;   damper means arranged in the duct for controlling a condition of the air flow in the air duct, said damper means comprising:   a pair of spaced-apart shafts each having an axis extending transverse of said opposing walls of the air duct, and being rotatably supported by said opposing walls of the air duct;   a film member having a first end fixedly connected to one of said shafts and a second end connected to the other of said shafts;   said film member having at least one opening through which the air duct is passed, for controlling a condition of the flow of air in the duct;   a first rotating body connected to said one shaft and rotable in the same direction as said one shaft, the first rotating body having an axis coaxial with said one shaft and defining an outer surface having a radius which varies proportionally along an axis thereof;   a second rotating body connected to the other shaft and rotable in the same direction as said other shaft, the second rotating body having an axis coaxial with the other shaft and defining an outer surface having a radius value which varies proportionally along an axis thereof;   a wire member having a first end connected to the first rotating body such that the wire member is able to be helically wound on said outer surface of the first rotating body, and a second end connected to the second rotating body such that the wire member is able to be helically wound on said outer surface of the second rotating body, and;   means for generating a resilient frictional force exerted substantially only in the wire moving between the first and second rotating bodies, to thereby impart a desired tension to the wire and thus obtain a desired engagement of the wire with the first and second rotating bodies.   
     
     
       6. An air conditioning apparatus according to claim 5, wherein said resilient frictional force generating means comprise a tensioning member arranged between the first and second rotating bodies such that the tensioning member is in contact with the wire member moving between the first and second rotating bodies, and spring means for generating a spring force so that a displacement of the tensioning member with respect to the wire in contact therewith is obtained, to thereby create a desired tension in the wire member. 
     
     
       7. An air conditioning apparatus according to claim 6, wherein said tensioning member is in the form of a movable rod able to be engaged with and displace the wire, and wherein said spring means is a coil spring having one end connected to the air duct and a second end formed integrally with said rod. 
     
     
       8. An air conditioning apparatus according to claim 6, wherein said tensioning member is provided with a lever rotatable with respect to the air duct, and a pair of guide pulleys in contact with the wire, at least one of the guide pulleys being mounted on the lever so that a tension is created in said wire when the lever is rotated by the action of the spring means.